首页 | 官方网站   微博 | 高级检索  
     

龙眼乳酸菌发酵工艺条件优化及其挥发性风味物质变化
引用本文:刘磊,汪浩,张名位,张雁,张瑞芬,唐小俊,邓媛元.龙眼乳酸菌发酵工艺条件优化及其挥发性风味物质变化[J].中国农业科学,2015,48(20):4147-4158.
作者姓名:刘磊  汪浩  张名位  张雁  张瑞芬  唐小俊  邓媛元
基金项目:国家自然科学青年基金(31301459)、国家“十二五”科技支撑计划(2012BAD33B10)、广东省自然科学基金(2014A030313568)、广州市珠江科技新星专项(201506010028)、广州市民生科技重大专项(201300000077)
摘    要:【目的】建立龙眼乳酸菌发酵的优化工艺条件,明确乳酸菌发酵前后其挥发性风味物质的变化,为龙眼功能性饮料的开发提供指导。【方法】采用梯度浓度驯化法将乳酸菌(保加利亚乳杆菌﹕嗜热链球菌=1﹕1)依次接入到含60%、70%、80%、90%(质量分数)龙眼果浆和10%脱脂乳的混合物中进行驯化,分析驯化过程中龙眼果浆酸度和p H的变化;以总酸为指标,通过Box-Benhnken中心组合试验设计优化乳酸菌发酵龙眼果浆的工艺条件,建立包括发酵时间、发酵温度、脱脂奶粉添加量和接种量的4因素回归模型;采用顶空固相微萃取和气相色谱-质谱联用的方法分析龙眼果浆发酵前后主要挥发性风味物质变化。【结果】(1)经过梯度浓度驯化后,得到了能在高浓度龙眼果浆中发酵的乳酸菌,经过12 h发酵,90%龙眼果浆的酸度由9.5oT升至104.4oT,p H由7.12降至4.44,其酸度显著高于60%和70%的龙眼果浆(P0.05),而p H与60%、70%和80%龙眼果浆无显著差异(P0.05)。(2)经回归模型并结合验证试验,确定乳酸菌发酵龙眼果浆的最佳工艺条件为:发酵时间12 h、发酵温度45℃、脱脂奶粉添加量5%、接种量3%。在该条件下,龙眼果浆的酸度由发酵前的9.5oT升为105.1oT,与模型预测值的相对误差为1.2%,可用于实际生产中预测。(3)龙眼果浆经乳酸菌发酵后其挥发性风味物质发生了显著变化。共有53种挥发性物质被检测出,其中萜烯烃类15种、醇类6种、酯类18种、酮类7种、醛类3种、酸类2种以及其他类2种。与发酵前相比,龙眼果浆发酵后新产生了18种挥发性风味物质。发酵后醇类、醛类、酯类、酮类和酸类挥发性风味物质的含量呈增加趋势,而萜烯烃类含量呈降低趋势。乳酸菌发酵龙眼果浆主要挥发性风味物质为乙醇25.68μg·g-1、4-(1-甲基乙基)-苯甲醇2.42μg·g-1、乙醛1.95μg·g-1、苯甲醛1.25μg·g-1、乙酸乙酯2.19μg·g-1、苯甲酸甲酯1.05μg·g-1、水杨酸甲酯1.93μg·g-1、3-羟基-2-丁酮1.085μg·g-1、反式-罗勒烯97.81μg·g-1、别罗勒烯1.923μg·g-1、乙酸1.84μg·g-1,其中苯甲醛和乙酸乙酯由发酵产生,乙醇、乙醛、别罗勒烯及乙酸经发酵后含量增加。【结论】乳酸菌发酵显著增加龙眼果浆的总酸及挥发性风味物质,通过优化控制发酵条件,可以开发风味独特的龙眼乳酸菌饮料新产品。

关 键 词:龙眼果浆  乳酸菌  发酵  挥发性风味物质  总酸
收稿时间:2015-04-23

Optimization of the Process Conditions and Change of Volatile Flavor Components of Longan Pulp Fermented by Lactic Acid Bacteria
LIU Lei,WANG Hao,ZHANG Ming-wei,ZHANG Yan,ZHANG Rui-fen,TANG Xiao-jun,DENG Yuan-yuan.Optimization of the Process Conditions and Change of Volatile Flavor Components of Longan Pulp Fermented by Lactic Acid Bacteria[J].Scientia Agricultura Sinica,2015,48(20):4147-4158.
Authors:LIU Lei  WANG Hao  ZHANG Ming-wei  ZHANG Yan  ZHANG Rui-fen  TANG Xiao-jun  DENG Yuan-yuan
Affiliation:Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610
Abstract:【Objective】The optical fermentation conditions of longan pulp by lactic acid bacteria were established, and the change of volatile flavor compounds of longan pulp before and after fermentation was clarified. This research can guide the development of functional longan beverage. 【Method】Lactic acid bacteria (Lactobacillus bulgavicus﹕Streptococus thermophilus=1﹕1) was domesticate in the medium containing 60%, 70%, 80% and 90% longan pulp and 10% skim milk. The acidity and pH of longan pulp were analyzed during the domestication. The conditions of fermented longan pulp by lactic acid bacteria were optimized through Box-Benhnken central composite experimental design based on the indicators of total acid. A regression model of four factors was established including the fermentation time, fermentation temperature, the content of skim milk powder and inoculation amount of lactic acid bacteria. Separation and analysis of the main volatile flavor compounds in longan pulp before and after fermentation were performed by headspace solid phase micro extraction and gas chromatography - mass spectrometry. 【Result】The lactic acid bacteria with good fermentation ability was obtained in longan pulp with high concentration. After 12 h of fermentation, the acidity of 90% longan pulp increased from 9.5ºT to 104.4ºT, and pH decreased from 7.12 to 4.44. The acidity of 90% longan pulp was significantly higher than that of 60% and 70% longan pulp (P<0.05), there was no significant difference of pH between longan pulp with four concentrations. The results showed that the optimum conditions are as follows: fermentation time 12h, fermentation temperature 45℃, 5% the content of skim milk powder and 3% inoculation amount of lactic acid bacteria. Under this condition, the acidity of fermented fruit pulp increased from 9.5ºT to 105.1ºT. The relative error to the value predicted by the model was 1.2%. It indicated that this model can be used in practical production. The volatile flavor compounds in longan pulp significantly changed after the fermentation. 53 volatile flavor compounds were detected in fermented longan pulp, which contained 15 terpenes, 6 alcohols, 18 esters, 7 ketones, 3 aldehyde, 2 acids and 2 others. 18 volatile flavor compounds were newly produced by fermentation. After the fermentation, the contents of alcohols, aldehydes, esters, ketones and acids increased, and the contents of terpenes decreased. The main volatile flavor compounds in fermented longan pulp were ethanol 25.68 μg·g-1, 4-(1-methylethyl)- benzenemethanol 2.42 μg·g-1, acetaldehyde 1.95 μg·g-1, benzaldehyde 1.25 μg·g-1, ethyl acetate 2.19 μg·g-1, methyl benzoate 1.05 μg·g-1, methyl salicylate 1.93 μg·g-1, 3-hydroxy-2-butanone 1.085 μg·g-1, (E)-β-ocimene 97.81 μg·g-1, allo-ocimene 1.923 μg·g-1, and acetic acid 1.84 μg·g-1, respectively. Benzaldehyde and ethyl acetate were newly generated. The contents of ethanol, acetaldehyde, allo-ocimene and acetic acid increased after the fermentation. 【Conclusion】 Lactic acid bacteria fermentation significantly increased total acid and volatile flavor compounds of longan pulp. Longan pulp beverage fermented by lactic acid bacteria with a unique flavor can be developed by controlling fermentation conditions.
Keywords:longan pulp  lactic acid bacteria  fermentation  volatile flavor compounds  total acid
本文献已被 CNKI 等数据库收录!
点击此处可从《中国农业科学》浏览原始摘要信息
点击此处可从《中国农业科学》下载全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号